1. Field of the Invention
The present invention relates to a solid-state image pickup device, and more specifically, it relates to a solid-state image pickup device including a solid-state image pickup element and a cover member fixed thereto and having a transparent flat plate portion.
2. Description of the Related Art
In recent years, with the reduction in size and thickness of digital cameras and cellular phones, a further reduction in size and thickness of solid-state image pickup elements has been applied.
So, a solid-state image pickup device is proposed that includes a solid-state image pickup element chip, and a cover member formed of a transparent material and having a flat plate portion and a frame portion integrally formed on the edge of the underside of the flat plate portion, the cover member being hermetically attached to the solid-state image pickup element chip.
In the case of a solid-state image pickup device disclosed in Japanese Patent Laid-Open No. 7-202152, the inner wall of the frame portion is perpendicular to the surface of the solid-state image pickup element. Therefore, in order to prevent unwanted light reflected by the inner wall of the frame portion from being incident on the light detecting elements, the frame portion is to be located away from the light detecting elements. For this reason, the solid-state image pickup device cannot be sufficiently reduced in size.
In the case of a solid-state image pickup device disclosed in Japanese Patent Laid-Open No. 2006-295481, the inner wall of the frame portion has an inclined surface that is inclined toward the light detecting elements with respect to the surface of the solid-state image pickup element. However, in order to sufficiently prevent moisture from entering from the outside, a relatively large bonding region is used between the frame portion and the solid-state image pickup element. Therefore, the solid-state image pickup device cannot be sufficiently reduced in size.
U.S. Patent Application Publication No. US 2008/0042227 describes forming a recess in a transparent plate by chemical etching or thermoforming processing. However, in order to prevent unwanted light reflected by the inner wall of a rib from being incident on the light detecting portion, the frame portion is to be located away from the light detecting portion. For this reason, the solid-state image pickup device cannot be sufficiently reduced in size.
In each example, achieving both the reduction of the solid-state image pickup device in size and the prevention of unwanted light from being incident on the light detecting elements is not considered.